U.S. patent number 4,425,976 [Application Number 06/279,700] was granted by the patent office on 1984-01-17 for small-type four-wheel automobile.
This patent grant is currently assigned to Suzuki Motor Company Limited. Invention is credited to Sukeaki Kimura.
United States Patent |
4,425,976 |
Kimura |
January 17, 1984 |
Small-type four-wheel automobile
Abstract
A small-type four-wheel automobile, especially one adapted to
carry one or two persons, has a generally U-shaped swing arm
pivotally connected at ends of its branched arms to a chassis frame
which supports front wheels, on this swing arm is mounted an engine
unit which includes a power train, from an engine to an axle for
rear wheels that serve as drive wheels, in a unitary
construction.
Inventors: |
Kimura; Sukeaki (Hamamatsu,
JP) |
Assignee: |
Suzuki Motor Company Limited
(JP)
|
Family
ID: |
27453450 |
Appl.
No.: |
06/279,700 |
Filed: |
July 2, 1981 |
Foreign Application Priority Data
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Nov 28, 1980 [JP] |
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55-166607 |
Jan 10, 1981 [JP] |
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56-1635 |
Jan 10, 1981 [JP] |
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56-1636 |
Jan 28, 1981 [JP] |
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56-10203 |
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Current U.S.
Class: |
180/56;
192/96 |
Current CPC
Class: |
B62D
31/003 (20130101); B60K 17/04 (20130101); B60K
5/04 (20130101); B60G 2300/13 (20130101) |
Current International
Class: |
B60K
5/00 (20060101); B60K 5/04 (20060101); B62D
31/00 (20060101); B60K 17/04 (20060101); B60K
005/04 () |
Field of
Search: |
;180/297,299,298,295,56,216,63,62,215,312,75
;192/27,70.29,89A,56R,96,19A ;464/15 ;188/18R-18A ;267/15R,57,154
;74/470,475,371-372 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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1048114 |
|
Dec 1953 |
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FR |
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1,483,387 |
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Apr 1967 |
|
FR |
|
Primary Examiner: Peters, Jr.; Joseph F.
Assistant Examiner: Roesch; Timothy
Attorney, Agent or Firm: McGlew and Tuttle
Claims
What is claimed is:
1. A small four wheeled automobile comprising:
a chassis frame having a forward end and a rear end;
a pair of front wheels rotatably mounted to said chassis frame near
its front end;
a U-shaped swing arm having a pair of branched arms with forward
ends pivotally mounted to said chassis frame at an intermediate
location thereon, said U-shaped swing arm including a rear cross
portion;
support means connected between said chassis frame adjacent its
rear end and said swing arm;
a cross rod connected between said pair of branched arms rearward
of said forward ends thereof;
an engine unit having a pair of shells defining a space and
containing an interconnected engine, transmission with drive shaft,
axle bearings and axle, said drive shaft rotatably mounted between
said pair of shells;
first cushion mounting means resiliently mounting a lower forward
portion of said engine unit to said cross rod;
second cushion mounting means resiliently mounting a rearward lower
portion of said engine unit to each of said branched arms and
around said axle;
a rear wheel connected to each end of said axle, said axle being of
a length so that a center to center distance between each rear
wheel is less than a center to center distance between each of said
front wheels and at most equal to a distance between pivotal
mountings of said pair of branched arms to said chassis frame.
2. An automobile according to claim 1, wherein said support means
comprises a single shock absorber connected between said rear
portion of said U-shaped swing arm and said chassis frame adjacent
the rear end thereof.
3. An automobile according to claim 1, wherein said engine unit
includes final reduction elements connected to said drive shaft and
axle respectively and engaged with each other disposed in a central
rear location in said pair of shells.
4. An automobile according to claim 2, wherein said transmission is
of the ball-lock type, said U-shaped swing arm and said chassis
frame being made of pipes, said U-shaped swing arm including a
pivot rod connected to said forward ends of said branched arms and
pivotally mounted by brackets to said intermediate location of said
chassis frame, a length of said pivot rod being greater than a
center to center spacing of each rear wheel, said front wheels
mounted on lateral outer sides of said chassis frame, said chassis
frame having a substantially horizontal forward end forward of said
intermediate location and a substantially horizontal rearward end
with an upwardly extending intermediate end containing said
intermediate location to which said U-shaped swing arm is pivotally
mounted, said engine of said engine unit lying forward of said axle
and over said first cushion mounting means.
5. An automobile according to claim 1, wherein said chassis frame
is bent midway obliquely upward toward the rear and then bent back
to extend horizontally.
6. An automobile according to claim 1, wherein said chassis frame
and said swing arm are both built of pipes.
7. An automobile according to claim 1, which uses a ball-lock type
transmission for said engine unit.
8. An automobile according to claim 3, wherein the final reduction
element for the rear axle is loosely fitted on said axle in such a
manner as to limit an axial sliding thereon, a dog clutch member
provided on one side of said element, and another dog clutch member
fitted on said axle slidably in the axial direction only, said
latter clutch member being normally urged in contact with the
former by a spring.
9. An automobile according to claim 7, wherein a driven lever for
operating a shift rod of said ball-lock type transmission and a
drive lever operatively coupled with a shift lever are loosely
supported by a common pivot, and the both levers are connected
together by a torsion spring.
Description
FIELD AND BACKGROUND OF THE INVENTION
This invention relates to a small-type four-wheel automobile.
Four-wheel automobiles of small sizes, esepcially those which carry
only one or two persons, are limited in engine power output, and
therefore the most important problem for the manufacturers is to
reduce the car weight to a minimum and whittle down the cost. In
addition, the vehicles are required to provide riding comfort, have
sufficient strength, and be easy to assemble, maintain, and
inspect, like ordinary passenger cars.
In meeting these requirements the small cars are not beyond being
improved in many points, e.g., in body frame configurations, engine
design, mechanisms that connect the engine with the driving wheels,
and in engine mounting on the chassis frame.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a four-wheel
automobile which is small in size, light in weight, and available
at low cost.
Another object of the invention is to provide a small-type
four-wheel automobile which runs with a minimum of vibration.
Still another object is to provide a small-type four-wheel
automobile with adequate strength.
Yet another object is to provide a small-type four-wheel automobile
of a construction which is easy to assemble, maintain, and
inspect.
Other objects and features of the invention will be apparent from a
reading of the following description in conjunction with the
accompanying drawings. In the drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view, in vertical section, of a small-type
four-wheel automobile embodying the invention;
FIG. 2 is a schematic plan view of the automobile of the invention,
with the car body eliminated to show the essential components;
FIG. 3 is a fragmentary, enlarged sectional view of the rear part
of the automobile according to the invention, showing how the
engine unit is mounted;
FIG. 4 is an enlarged plan view of the rear part of the automobile
of the invention, with the rear-axle assembly and one of the rear
wheels shown in section;
FIG. 5 is a fragmentary enlarged view of the swing arm carrying the
engine unit, as seen from the front of the vehicle;
FIG. 6 is an exploded view of the swing arm and the engine
unit;
FIG. 7 is a sectional view of the engine unit with the power
train;
FIG. 8 is an enlarged sectional view of the transmission in the
power train;
FIG. 9 is a sectional view taken on the line A--A of FIG. 8;
FIG. 10 is a partly sectional view of the lever connections, as
seen in the direction of the arrow B in FIG. 8;
FIG. 11 is a partly sectional view of the arrangement of FIG. 8,
illustrative of the power transmission between the levers;
FIG. 12 is a sectional view of the power train mechanisms between
the transmission and the rear axle; and
FIG. 13 shows a dog clutch between the final reduction element and
the rear axle in FIG. 12 in mesh.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 there is shown a small-type four-wheel
automobile 1 with a capacity of one person, as an embodiment of the
present invention. This automobile 1 comprises a chassis frame 2 of
pipes, a pair of front wheels 3 secured to both the front sides of
the frame 2, a swing arm 4 of pipes pivotally connected at the
front ends of its branched arms to intermediate portions of the
frame 2, an engine unit 5 mounted on the swing arm 4, a pair of
rear wheels 7 supported by a driving axle 6 which forms part of the
engine unit 5, a steering wheel 8, and a car body 9 of synthetic
resin material.
The engine 10 is formed integrally with a case 11, which in turn
encloses the associated parts, from the transmission to the
bearings of the driving axle 6. The engine 10, transmission, axle
bearings, and case 11 combinedly constitute the engine unit 5.
The chassis frame 2 is bent midway, obliquely upward toward the
rear and then bent back to extend horizontally. At about the middle
point of the frame is provided a cross member 12. The swing arm 4
is generally U-shaped, with both its front ends rigidly attached to
a rod 13 of a tubular structure. It is pivotally connected to the
portions of the chassis frame 2 a short distance behind the cross
member 12, through the rod 13 and brackets 14.
As shown in FIG. 4, the rod 13 is longer than the driving axle 6.
Accordingly, the center-to-center distance, or tread, of the
driving rear wheels 7 is narrower than the tread of the front
wheels 3. (Refer to FIG. 2.)
Between the rear centers of the swing arm 4 and the chassis frame 2
is provided a shock absorber 15 with brackets 16 at both ends which
act as support means for the swing arm.
A rod 17 is extended across and secured at its ends to intermediate
points of the two branched arms of the swing arm 4. To the middle
portion of this rod 17 are secured, as shown in FIGS. 5 and 6, a
pair of upright ears or brackets 18, which in turn receive
therebetween a mounting bracket 19 protruding downward from a
middle point of the under surface of the engine 10. With a bolt 20
inserted through holes of these brackets and fastened with a
cushion 21, washer 22, and nut 23, the front part of the engine
unit 5 is mounted on the swing arm 4. This forms first cushion
mounting means
On the rear portions of the branched arms of the swing arm 4 are
secured rear axle brackets 24, which support the driving axle 6 at
two points, each with a retainer 25, cushion 26, and bolts 27. In
this way the rear part of the engine unit 5 is also mounted on the
swing arm 4 by second cushion mounting means.
As better shown in FIG. 7, the case 11 includes a left and a right
shells 28, 29, which can be divided into two in the direction
normal to the axis of the rear axle 6 (in the longitudinal
direction as viewed in the figure). Inside the case 11 there are
rotatably supported a crankshaft 30, countershaft 31, and drive
shaft 32 of the engine 10, and the middle portion of the rear axle
6. The portion of the crankshaft 30 inside the shell 29 carries an
automatic clutch 33 for the lower drive range and an automatic
clutch 34 for the high range.
The crankshaft 30 and the countershaft 31 are operatively connected
by gears 35, 36 in mesh, so that the rotary motion can be
transmitted from the crankshaft 30 to the countershaft 31. The
latter shaft is supported at one end and at a middle point by
bearings 37, 38, and an oil pump 39 is attached to the other end.
To a reduced-diameter portion of the countershaft 31 near the
bearing are press fitted a gear 40 for the low range and a gear 41
for the drive range. Another gear 42 for reverse is provided
adjacent the drive-range gear 41.
The driveshaft 32 is a hollow one supported by bearings 43, 44, and
a shift rod 46 is inserted from the shell 28 into the center bore
45 of the shaft 32. The shift rod 46 has a bulge 47, which is
adapted to engage any one of balls 51, 52, 53 (FIG. 8) formed in
the drive shaft 32, so that the drive shaft 32 can be selectively
coupled with one of change gears 54, 55, 56 loosely fitted on the
drive shaft 32. When the driver causes the shift rod 46 to move
forward or backward, the bulge 47 on the rod will force the ball
51, 52, or 53 radially outward into engagement with one of recesses
57, 58, or 59, respectively, formed in the gears 54, 55, and 56,
thus operatively connecting the drive shaft 32 with one of the
gears 54, 55, 56.
In FIG. 8, holes 48, 49, 50 are formed radially of the drive shaft
32, one each for the gears 54, 55, 56 they face, in such a manner
that the single ball 51, 52, or 53 can couple the drive shaft 32
with the gear 54, 55, or 56. Alternatively, as shown in FIG. 9, the
gear 54 (as well as the other gears 55 and 56) may have two holes
48 formed to receive two balls 51 instead of one.
On the front end portion of the rod 46 extended away from the drive
shaft 32 is fitted a sleeve 62, which is adjustable in position by
means of adjust nuts, 60, 61. The numeral 63 denotes a first lever
and 64, a second lever. These two levers 63, 64 are turnably
connected at one end, as in FIG. 10, to a pin 66 extending from a
bracket 65, which in turn are secured to the inner wall surface of
a gear case 68 by bolts 67. The levers 63, 64 are joined togehter
by a coiled torsion spring 69 to maintain a normally straight
relationship. Thus, given a force stronger than that of the torsion
spring 69, the two levers 63, 64 would yield, naturally shifting
their positions relative to each other. The levers 63, 64 and the
torsion spring 69 constitute a lever unit 70.
At the other end of the first lever 63, a connector 72 attached to
one end of a remote-control wire 71 is pivotally connected by a pin
73. The remote-control wire 71 transmits forces in the pushing
direction as well as in the pulling direction. In this sense it
acts like a rod. The opposite end of the wire 71 is connected to a
shift lever 74 in the driving compartment. As indicated, the lever
is operated to place the gears in the position marked with "1",
"2", "N", or "R", and then a shift to the low driving range, high
range, neutral, or reverse is completed.
A part of the first lever 63 is expanded to a sector form inwardly
of the gear case 68, and the curved periphery of the sector has
recesses 76, 77, 78, 79 formed to correspond to the number of gear
positions to be shifted. One of these recesses 76, 77, 78, 79 is
engaged with a pawl 81 formed at the free end of an arm 80. The arm
80 is supported at the other end by a pivot 82 and is normally kept
in the engaged position under the urging of a spring 83. The sector
75 and the arm 80 constitute a positioner for the shift rod 46.
Turning to FIG. 10, the second lever 64 is shown bifurcated in the
lower half, with lugs 84 attached to the inner sides and fitted in
corresponding recesses of the sleeve 62.
As is clear from FIG. 8, the shift rod 46 has a marking 85 in the
form of a light streak formed, e.g., by turning on a lathe. This
marking 85 is provided at a distance L' from the center of the
bulge 47 of the rod 46. The distance L' is chosen on the basis of
the distance L between the center of the hole 48 for the ball 51
and the outer end of the drive shaft 32, in the relation L'=L or
L'=L+.DELTA.L .
The marking 85 serves as a guide when the shift rod 46 is to be
inserted into the hollow drive shaft 32. In assembling these and
associated component parts the operator can find the amount of the
shift rod 46 inserted into the drive shaft 32 from the relative
position of the marking 85 and the shaft end and then tighten the
adjust nuts 60, 61 properly.
On the inner end portion of the drive shaft 32, which is close to
the bearing 43, is press fitted a sprocket 86 as a speed reduction
element on the driving side of a final reduction gear. An endless
chain 88 is extended around this sprocket 86 and also around a
sprocket 87 fixedly mounted on the axle 6 as a reduction element on
the power output side. Since the sprocket 87 is aligned to the
sprocket 86, there is provided a space 89 in the shell 28 of the
case 11.
In the power train of the construction described above, the rotary
motion of the crankshaft 30 is transmitted through either the
automatic clutch 33 for the low drive range or the automatic clutch
34 for the high range to the countershaft 31. The motion is thence
transmitted to the drive shaft via the low-range gear 40,
drive-range gear 41, or reverse gear 42 attached to the
countershaft 31 and further through one of the change gears 54, 55,
56 selected by means of the shift rod 46.
The operation of the transmission gear will now be explained.
First, in the state shown in FIG. 8, the shift lever 74 rests in
the low-range "1". The lever unit 70 and the shift rod 46 linked by
the remote-control wire 71 maintain the angles and positions
corresponding to the angle and position of the shift lever 74.
Thus, the bulge 47 of the rod 46 is located inside the low-range
gear 54, pushing the ball 51 radially outward to couple the drive
shaft 32 and the gear 54 together.
Shifting from this to the high-range position "2" is accomplished
in the following way. To begin with, the driver disengages the
clutch (not shown). In case where the clutch is of an automatic
type, he simply raises his foot off the accelerator pedal.
Following either operation, the driver moves the shift lever 74 to
the "2" position. This causes the first lever 63 to turn
counterclockwise as viewed in FIG. 8, about the pivot 66.
Accordingly, the pawl 81 is disengaged from the recess 76 into
enagagement with the next recess 77, as shown better in FIG. 11.
The second lever 64 too turns in the same direction as the first
lever 63 by virtue of the torsion spring 69, pushing the rod 46
rightward as viewed in FIG. 8. This enables the bulge 47 to release
the ball 51 but force the next ball 52 radially outward to couple
the gear 55 with the drive shaft 32. The rotation of the drive
shaft 32 is now carried to the axle 6 by way of the sprocket 86,
endless chain 88, and sprocket 87.
Another embodiment of the final reduction gear for this power train
will be described with reference to FIGS. 12 and 13. The sprocket
87 on the output side of the final reduction gear is loosely fitted
on the axle 6 and carries a clutch member 90 on one side. Another
clutch member 92 is fitted in splines 91 formed on the axle 6.
These clutch members 90 and 92 are formed with recesses 93 and cam
projections 94, respectively, so that the cam projections 94 formed
on the clutch member 92 mesh with the recesses 93 of the clutch
member 90. The clutch member 92 is normally urged by a spring 95,
which is supported at one end by a portion of the axle 6, in the
direction where the cam projections 94 remain fitted in the
recesses 93. The clutch member 92 and the spring 95 are both
accommodated in the space 89.
In the power train of the foregoing construction the rotation of
the sprocket 87 driven by the endless chain 88 is carried to the
axle 6 through the clutch member 92. Any impact which may result
from the meshing of gears during the manipulation for a gear change
can be absorbed because the clutch member 92 retracts, compressing
the spring 95.
The two rear wheels 7 of the small-type four-wheel automobiles
embodying the invention, as shown in FIG. 7, comprise wheel bodies
96 attached to the both ends of the axle 6, and tires 97 whose rims
98 are fastened to the wheels by bolts 99. These rear wheels 7 are
driven by the axle 6 that receives the power from the engine by
means of the sprocket 87 in the manner described, and therefore the
both wheels 7 run together likewise at the same time. For this
reason a brake 100 is provided for only one of the rear wheels, and
naturally the axle bearing structures for the left and right
portions of the axle 6 differ from each other.
The bearing structure on the left hand of the axle 6 as viewed in
FIG. 7 comprises a tubular cushion 26 of rubber fitted in the
recess of the already mentioned bracket 24, and a cylindrical
portion 101 of the case 11 located in the cushion, through which
the axle 6 extends leftward. On the other hand, the bearing
structure on the right hand of the axle 6 as in FIG. 7 comprises a
cushion 26 similar to the left one fitted in the recess of the
bracket 24, and a metal sleeve 102 of iron located in the
cushion.
The metal sleeve 102 has flanges 103, 104 welded to the both ends,
and also has an upright lug 105 provided in the vicinity of the
flange 103. The flange 103 has a hole 106, through which a bolt 107
is inserted to fasten the inner end of the sleeve 102 to the case
11. When the sleeve is so fastened the lug 105 contacts the inner
end of the cushion 26 to keep it in position. The flange 104 at the
outer end of the metal sleeve 102 supports the brake 100, which is
of a conventional design and the description is omitted.
When the small vehicle of the construction described is running and
is to be stopped, the brake 100 is applied. The braking force so
exerted, in turn, produces a reaction force on the stationary side
of the brake 100. This reaction force is transmitted through the
metal sleeve 102 that supports the brake 100 to the case 11 and is
taken up by the latter. In this case, the metal sleeve 102 of a
tough material used will adequately receive and absorb the reaction
force, despite the considerable distance between the case 11 and
the rear wheel 7.
As will be obvious from the foregoing description of the
embodiment, the small-type four-wheel automobile of the invention
is made small in size and light in weight by the use of an engine
unit that comprises the power train, from the engine to the rear
axle that drives the wheels, in a unitary construction. In
addition, the vehicle efficiently absorbs the vibrations that
result from the running on roads and also kills the vibrations of
the engine itself by the cushions interposed between the engine
unit and the swing arm.
The small four-wheel automobile according to the invention, with
its engine unit mounted on the swing arm, does not require powerful
shock absorbers of high damping forces but needs only one shock
abosrber. This combines with the adoption of the chassis frame and
swing arm of pipes to realize a further reduction of the overall
weight.
The automobile according to the invention eliminates the universal
joint and differential gear of the ordinary vehicles by narrowing
the center-to-center distance, or tread, of the rear wheels as
compared with that of the front wheels. The car weight is
accordingly whittled down.
Also, in the automobile of the invention, the distance between the
portions of the swing arm pivotally connected to the chassis frame
is either equal to or greater than the center-to-center distance,
or tread, of the rear wheels. The swing arm thus possesses
sufficient torsional strength to withstand turning motions and
enable the vehicle to make stable turns.
The automobile according to the present invention is easy to
assemble, maintain, and inspect. This is because the case of the
engine unit is partitioned in the direction normal to the axis of
the axle, and the engine unit is housed in one of the case
compartments, with the final reduction elements of the engine unit
being accommodated in the deepest region of the compartment.
Furthermore, in the small-type four-wheel automobile of the
invention, the final reduction elements are coupled to the rear
axle by the clutch that is resiliently engaged by virtue of the
spring, and the shift lever and the shift rod are coupled by way of
the torsion spring. These arrangements prevent the transmission of
excessive forces and thereby protect the compartment parts from
damage.
* * * * *